Power operated single blade knife



Dec. 26, 1967 J. M. HANSEN 3,359,637

POWER OPERATED SINGLE BLADE KNIFE Filed Oct. 25, 1966 Fug--35 44 40INVENTOR.

F I JOHN M. HANSEN ATTORNEY United States Patent 3,359,637 POWEROPERATED SINGLE BLADE KNIFE John M. Hansen, Racine, Wis., assignor toScovill Manufacturing Company, Waterbury, Conn., a corporation ofConnecticut Filed Oct. 25, 1966, Ser. No. 589,274 8 Claims. (Cl. 30-272)This invention relates to a power operated knife in which a single bladehas reciprocating motion imparted thereto by a motor driven pinion whichdrives a spur gear provided with an integrally molded single cam on theface of the spur gear.

One object of the invention is to provide simple and eflicient means formounting the blade tang in a reciprocated carrier, whereby the blade islocked in the carrier by insertion of the tang in the carrier intoengagement with a spring steel blade retainer, releasable by a releasebutton mounted in the knife housing.

Another object of the invention is to mount the reciprocated partsincluding the carrier and the blade tang in a cage stationarily mountedin the housing adjacent the forward end of the housing. The cage isformed to enclose the carrier and antifriction means between the carrierand cage which greatly prolong the life and performance of the batterypower source used in the knife to drive the motor, with minimum ofcurrent drain. The forward end of the cage bears against a boot made ofthermolastic material which provides a yielding end bearing for the cageand contents. Antifriction means between the carrier and cage areNylatron rollers located in longitudinally spaced apart pairs above andbelow the carrier top and bottom surfaces.

In the drawings:

FIG. 1 is an elevational side view of the knife mechanism with the outerhousing shown in longitudinal vertical section.

FIG. 2 is a top plan view of part of the knife mechanism, with the outerhousing shown in horizontal section.

FIG. 3 is a longitudinal vertical sectional view in the plane of theline 33 of FIG. 2.

FIG. 4 is a transverse vertical sectional view in the plane of the line44 of FIG. 2, on an enlarged scale.

FIG. 5 is a transverse vertical sectional view in the plane of the line5-5 of FIGS. 1 and 3, on an enlarged scale.

In the embodiment of the invention shown in the drawings, a housingencloses a motor 11, battery pack 12, pinion 13 on motor shaft 14, spurgear 15 with cam 16 on one of its faces, and cage 17 in which a bladecarrier 13 is reciprocably contained. The spur gear 15 with cam 16 isloosely mounted on the transverse shaft 19. The cage 17 is generallyrectangular steel casing having top, bottom and side walls, with strapmembers 20 at opposite sides riveted to the side walls of the cage, andoffset for attachment to support brackets 21 attached to the motor 11.The brackets 21 also support the transverse shaft 19. The forward end ofthe cage contacts a boot 22 made of thermolastic material which isyielding and provides a resilient end bearing for the cage 17. The boot22 has an inner concave-convex portion 23 which has a vertical slit 24therein for passage of the knife tang 25 therethrough.

The carrier or driver 18 imparts reciprocated movement to the blade 25.The carrier has two pairs of roller engaging surfaces extending,transversely of the carrier on the upper and lower faces thereof, onepair of said surfaces 30 being spaced longitudinally of the carrier fromthe other as shown in FIGS. 3 and 4. Rollers 31 rest on the surfaces 30between said surfaces and the upper and lower walls of the cage 17. Theouter surfaces of the carrier between the upper and lower roller bearingsurfaces 30 are recessed as indicated at 32 in FIG. 4 to provide lateralspaces 33 between the carrier sides and the side walls of the cage 17Midway between the two pairs of roller bearing surfaces 30, the carrier18 is cut away to form a portion 18' (FIG. 5) which is narrowertransversely than the rest of the carrier (FIG. 4). The portion 18' iscut away to provide an opening 34 extending transversely therethrough,the surfaces 35 adjacent the opening being inclined as shown in FIG. 5.The carrier 18 has a longitudinally extending centrally located space 36for reception of the tang 25 of a blade. The tang 25 has a hole 37extending transversely therethrough which registers with the opening 34in the carrier 18 when the tang has been inserted in the carrier apredetermined distance. A blade retainer 40 made of spring steel is aswide as the portion 18 of the carrier 18 as shown in FIG. 3, and isformed with side arms 41 to fit the sides of the carrier, one of saidside arms 41 terminating in an inwardly curved blade retainer 42 asshown in FIG. 5. The retainer 42 partially enters the hole 37 in theblade tang 25 when the tang has been inserted sufliciently to bring theopenings 37 and 34 into register with each other. The blade retainerarms 41 extend downwardly beyond the carrier 18 and are joined by across piece 43 spaced from the bottom of the carrier in position to becontacted by a blade release member 44 mounted in the housing 10 and provided with a button 45 for engaging the cross piece 43 of the retainer40. The release member 44 is made of resilient thermolastic material.

Rearwardly of the carrier parts herein described, the carrier isprovided with an opening 46 for receiving the cam 16 on spur gear 15.

Motor control switch lever 47 actuates contact 48 for opening or closingthe switch between the batteries and motor. 1

To use the knife, the blade tang 25 is inserted through the slit 24 inthe boot 22, into the passage 36 of the carrier 18, until the hole 37 inthe tang registers with the opening 34 in the carrier and the bladeretainer part 42, bearing against the inclined surfaces 35, snaps intothe hole 37 and firmly holds the blade in its intended position in thecarrier 18. The carrier is slidably held within the cage 17, with therollers 31 bearing on the upper and lower surfaces of the carrier inlongitudinally spaced apart locations. Closing of the switch contacts 48actuates the motor, driving the pinion 13, spur gear 15 and cam 16, toreciprocate the carrier 18 and the blade held therein.

To release the blade tang 25 from carrier 18, the blade release member44 is manually pressed inwardly to move the button 45 into contact withthe cross piece 43 of the retainer 40. This movement causes the arms 41of the retainer to move upwardly, forcing the retainer member 42 toslide out of engagement with the blade tang and permitting the blade tobe removed. Retainer 40 automatically returns to normal position aftermanual release of button 45.

In describing the invention, reference has been made to a particularexample embodying the same, but I wish it to be understood that theinvention is not limited to the construction shown in the drawing andthat various changes may be made in the construction and generalarrangement of parts without departing from the invention.

I claim:

1. A power operated knife comprising (a) a housing,

(b) an electrically powered motor in the housing,

(0) a cage adjacent the forward end of the housing,

(d) a blade carrier reciprocably mounted in the cage,

the carrier having a blade tang receiving space extending longitudinallyof the carrier and a laterally extending aperture,

(e) a blade having a tang provided with a laterally extending aperturein register with the carrier aperture when the tang has been inserted inthe carrier a predetermined distance, I

(f) a spring metal blade retainer having a pair of arms adapted toengage opposite sides of the carrier, a cross piece connecting the armsspaced from the carrier, and inwardly directed tang engaging member onone of said arms for entering the apertures in the carrier and bladetang and retaining the tang in the carrier,

(g) blade release means in the housing movable into contact with saidretainer cross piece for moving said blade retainer relatively to thecarrier and disengaging the inwardly directed member from the aperturesin the carrier and tang to release the blade and (h) means between themotor and carrier imparting reciprocatory movement to the carrier.

2. The power operated knife defined by claim 1, in which the bladecarrier is spaced from the cage, and which includes two pairs of rollersspaced apart longitudinally of the housing, the rollers of each pairbeing located between upper and lower surfaces of the carrier and thecage.

3. The power operated knife defined by claim 1, in which the carrier isprovided with a groove extending around the carrier between its ends forreception of the spring metal blade retainer arms.

4. The power operated knife defined by claim 1, in which the carrier isprovided with inclined surfaces surrounding the carrier aperture, saidsurfaces being inclined inwardly toward said aperture.

5. The power operated knife defined by claim 1, which includes a bootmade of resilient material located between the blade carrier and theforward end of the housing, said boot having a vertical slit thereinthrough which the blade tang is inserted into the carrier.

6. The power operated knife defined by claim 1, in which the means forimparting reciprocatory movement to the carrier comprises a motor shaft,a pinion on the shaft, a spur gear driven by the pinion, and a cam onthe gear in engagement with the carrier.

7. The power operated knife defined by claim 1, in which the carrier hasside walls spaced from the cage, and the blade retainer arms areslidable on said side walls in one direction when contacted by saidblade release means and automatically slidable in the opposite directionwhen the blade release means is out of contact with the blade retainer.

8. A power operated knife comprising (a) a housing,

(b) an electrically powered motor in the housing,

(c) a blade carrier reciprocably mounted in the housing, the carrierhaving a blade tang receiving space extending longitudinally of thecarrier and a laterally extending aperture,

(d) a blade having a tang provided with a laterally extending aperturein register with the carrier aperture when the tang has been inserted inthe carrier a predetermined distance,

(e) a spring metal blade retainer having a pair of arms adapted toengage opposite sides of the carrier, a cross piece connecting the armsspaced from the carrier, and an inwardly directed tang engaging memberon one of said arms for entering the apertures in the carrier and bladetang and retaining the tang in the carrier, 7

(f) blade release means in the housing movable into contact with saidretainer cross piece for moving said blade retainer relatively to thecarrier and disengaging the inwardly directed member from the aperturesin the carrier and tang to release the blade and I (g) means between themotor and carrier imparting reciprocatory movement to the carrier.

References Cited UNITED STATES PATENTS 2,721,586 10/1955 Hill l4368.53,234,649 2/1966 Treble et a1. 30272 3,307,259 3/1967 Christensen 30-2723,337,954 8/1967 Robinson 30-272 JAMES L. JONES, JR., Primary Examiner.

1. A POWER OPERATED KNIFE COMPRISING (A) A HOUSING, (B) AN ELECTRICALLYPOWERED MOTOR IN THE HOUSING, (C) A CAGE ADJACENT THE FORWARD END OF THEHOUSING, (D) A BLADE CARRIER RECIPROCABLY MOUNTED IN THE CAGE, THECARRIER HAVING A BLADE TANG RECEIVING SPACE EXTENDING LONGITUDINALLY OFTHE CARRIER AND A LATERALLY EXTENDING APERTURE, (E) A BLADE HAVING ATANG PROVIDED WITH A LATERALLY EXTENDING APERTURE IN REGISTER WITH THECARRIER APERTURE WHEN THE TANG HAS BEEN INSERTED IN THE CARRIER APREDETERMINED DISTANCE, (F) A SPRING METAL BLADE RETAINER HAVING A PAIROF ARMS ADAPTED TO ENGAGE OPPOSITE SIDES OF THE CARRIER, A CROSS PIECECONNECTING THE ARMS SPACED FROM THE CARRIER, AND INWARDLY DIRECTED TANGENGAGING MEMBER ON ONE OF SAID ARMS FOR ENTERING THE APERTURES IN THECARRIER AND BLADE TANG AND RETAINING THE TANG IN THE CARRIER, (G) BLADERELEASE MEANS IN THE HOUSING MOVABLE INTO CONTACT WITH THE RETAINERCROSS PIECE FOR MOVING SAID BLADE RETAINER RELATIVELY TO THE CARRIER ANDDISENGAGING THE INWARDLY DIRECTED MEMBER FROM THE APERTURES IN THECARRIER AND TANG TO RELEASE THE BLADE AND (H) MEANS BETWEEN THE MOTORAND CARRIER IMPARTING RECIPROCATORY MOVEMENT TO THE CARRIER.